Pulsating fluid pumping system

ABSTRACT

The pumping system can be utilized wherever pulsatory fluid pumping is expedient or possible. The system is distinguished by the fact that the positivedisplacement pump employed therein is submerged into the fluid being pumped so, that the hole for fluid ejection is located below the level of this fluid, and the inner space of the pump working chamber permanently communicates with the fluid to be pumped.

United States Patent 1191 Makarov et al. 1 Jul 9 1974 ['5 PULSATINGFLUID PUMPING SYSTEM 2,496,711 2/1950 Goddard 417/394 X 2,854,003 9/1958K'rsch 128/233 [76] Inventors it A f?{,, zg j 3,550,162 12/1970 Hi1ffmanat al.. 417/394 x i roralon 3,689,204 9/1972 Prisk 4I7/479X GrigorievichMaximov, mikroraion i hi i i fig g i ,xi gj 'g s Primary ExaminerWilliamL. Freeh 24 an of Puschino M Osk ovsk i Assistant Examiner-Richard E.Gluck Oblasti U SS R Attorney, Agent, or FirmEric H. Waters [22] Filed:Mar. 10, 1972 [57] S RACT [211 App]. N0.: 233,457 i H v The pumpmgsystem can be utllized wherever pulsa- I tory fluid pumping is expedientor possible. {2?} i258! :3':' '.'"::'::::'"i'narasyiwnilififi s isdssssssssshss by we fsss shss s [58] Field 128/253 232pos1t1ve-d1splacement pump employed therein 1s i submerged into thefluid being pumped so, that the 417/479 239/339 hole for fluid ejectionis located below the level of this fluid, and the inner space of thepump working [56] References Clted chamber permanently communicates w1ththe flu1d to UNITED STATES PATENTS be pumped 5I5,898 3/l894 Brainard 23/23 X 1,736,643 11/1927 Beck 417/92 X 1 Claim, 1 Drawing FigurePULSATING PRESSURE SOURCE.

PATENTEUJUL w 3,822,968

PULSATING PRESSURE SOURCE.

l PULSATING FLUID PUMPING SYSTEM The advantage of this pumping systemconsists in that it has a simple design and small size, requires a smallamount of costly biological fluid compared with existing apparatus ofthis kind, and prevents the appearance of stagnation zones in the fluidbeing pumped and the foaming of the fluid as a result of energeticejection. The latter is an advantage in itself. Exclusion of foamingwidens the field of application of these systems. Such systems are to bemainly employed in biological laboratory units where foaming andformation of stagnation zones are not allowable.

The present invention relates to pumping systems, and more specificallyto pulsatory pumping systems for fluids, mainly for biological nutrientmedia in installations to maintain life activity of biological cells andtissues.

Widely known are laboratory pumping units for maintaining life activityof biological tissues and cells. In these units fluid is circulated by apositivedisplacement trickling pump consisting of two vessels located atdifferent levels, one of the vessels, the upper one, supplying the fluidthrough a dropper, and the other, the lower one, receiving the pumpedfluid.

The disadvantage of such pumpingsystems consists in the difficulty tomaintain constant pressure in the upper vessel.

To keep pressure at the required level additional devices are used whichprovide for permanent replenishment of fluid, or regulate pressure inthe upper vessel according to a prescribed law. This significantlycomplicates the unit in production and operation.

Besides that, pumping systems with such pumps have large overalldimensions determined by the mutual disposition of the chamber with thebiological tissues or cells, and the supplying and the receivingvessels.

What is more, such a system requires a large amount of extremelyhard-to-get nutrient fluid to fill it.-

Since units of this type feature certain operating cycles connected withthe need to empty the upper vessel, such units require a separate pumpfor returning the fluid from the lower vessel to the upper one, whichfurther raises the complexity and cost of the unit.

Also known are systems for jerk pumping of molten metals. In thesesystems the positive-displacement jerk pump consists of two coaxiallydisposed tubular cham' bers, the lower end of the inner tubular chambercommunicating with the outer chamber, and the upper end of this samechamber extending beyond the outer chamber and being connected with theconsumer of the pumped fluid, while the outer tubular chamber has at itsbottom inlet holes and at its top communicates with a pulsatory sourceof compressed air. Such a pump must be submerged to a considerable depthinto the J fluid metal to be pumped. As pressure is fed to the outerchamber, metal is pressurized into the inner chamber wherefrom under apressure pulseit flows to the consumer.

(Such systems are known, for example, from a USSR Authors CertificateNo. 250,391, cl. 31b2, 39

The disadvantage of these pumping systems consists in that the pumpedmedium therein is liable to foam in the zone of suction. Therefore thesesystems cannot be used in installations wherein foaming is completelyinadmissible. For example, these pumping systems cannot be utilized ininstallations for maintaining the life activity of biological tissues.

Another disadvantage of these systems is their low volumetricefficiency, since at each pressurization stroke considerable volumes ofthe pumped fluid are wastefully thrown out through the suction hole ofthe pump outer tubular chamber.

One more disadvantage is the slow rate of fluid suction into the outerchamber, as the intensity of suction is only defined by the depth of thepump submersion into the fluid. Increased depth of pump submersioninvolves enlarged overall dimensions of the pump and of the installationas a whole, and besides, causes formation of stagnant pockets within thefluid volume. The latter circumstance results in the melt freezing.Formation of stagnant zones is always undesirable, especially 'ininstallations for maintaining life activity of biological tissues.

An object of the invention is to rule out foaming of the medium in thezone of suction.

Another object is to raise the efficiency of the system.

Further objects of the invention are to improve the suction intensity ofthe pump and to exclude formation of stagnation pockets in the fluidbeing pumped.

With these objects in view, in a positive-displacement pumping systemserving for pulsatory fluid pumping, according to the invention, part ofthe pump housing with the fluid ejection hole is submerged into thefluid being pumped so that through this hole the inner space of the pumpchamber permanently communicates with the fluid to be pumped.

More particularly, the housing of the positivedisplacement pump consistsof a chamber having elastic walls enclosed with a clearance in a chamberhaving rigid walls, wherein said clearance should communicate with apulsatory pressure source.

Such a pumping system provides for intense ejection of the portion offluid (which is determined by the pump displacement) and similarlyintense suction of a new portion with a minor stirring effect on thefluid in the zone of suction-compression.

Exclusion of foaming is due to the'high rate of passage of the fluidportion through the layer of fluid medium, and intense suction issecured by the vacuum built up in the working chamber of the pump.

Following is a detailed description of the invention in a preferredembodiment thereof, namely as applied to an installation for maintaininglife activity of biological cells and tissues, with references to theappended drawing which shows the installation to maintain the lifeactivity of biological tissues and cells according to the invention.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a schematic view of thepumping arrangement in accordance with the present invention.

The installation comprises an auxiliary chamber 1 wherein placed are thebiological tissue or cells 2, this chamber communicating through apiping 3 with a storage vessel 4 of the biological nutrient fluid.

Vessel 4 communicates with an aerator 5 which in turn communicates withchamber 1.

Pipes 6 and 7 serve, respectively, for delivering and I removing a gasmedium required to aerate the nutrient fluid. The nutrient medium iscirculated by means of a positive-displacement pump 8. The latterconsists of two chambers located with a clearance one inside the other:an outer chamber 9 and an inner working chamber 10 with elastic walls11. Chamber 10 in its upper part terminates in a narrowing pipe 12having rigid walls.

Provided at the end of pipe 12 is a hole 13 for the fluid ejection. Thepump is mounted in vessel 4 so that hole 13 of pipe 12 is below thelevel of the nutrient fluid 14.

Through hole 13 the inner space of the working chamber 10 permanentlycommunicates with the nutrient fluid 14 to be pumped.

The space of the clearance between the outer chamber 9 and the innerchamber 10 communicates by means of an air pipeline 15 with a pulsatorypressure source, Le. a pneumatic generator 16.

The installation operates as follows.

As an air pulse is fed from the pulsating pressure source 16 through theair pipeline 15 to the clearance between chambers 9 and 10, the elasticwalls 11 of chamber 10 are strained.

This causes ejection of a portion of fluid from chamber 10 through hole13 of pipe 12, this portion of fluid is then thrown onto the wall ofaerator 5, wherein circulating gas serves to aerate the nutrient fluid.Circulation of gas is achieved due to delivery of the gas along pipe 6and its removal through pipe 7. This portion of fluid spills down thewall of aerator 5 into chamber 1 wherein the biological tissue or cellsare located.

After the air pulse is stopped the resilient walls 11 of chamber 10under the effect of elastic forces return to their initial position,fluid 14 being intensely sucked from vessel 4 into chamber 10.

The pulse feeding and stopping cycles are continuously repeated so as toattain a pulsatory supply of the portions of fluid 14 into chamber 1,thus simulating natural life conditions of the biological tissue.

As the nutrient fluid l4 accumulates in chamber 1, the levels of fluidin vessel 4 and chamber 1 are equalized, so that a current of thenutrient fluid through chamber 1 is realized, and hence, an exchangeoccurs of this fluid around the biological tissue (cells) 2.

Owing to the fact that the nutrient fluid 14 passes through aerator 5 insmall portions and spills down its walls, maximum saturation is achievedof the nutrient fluid with the gases required for the life activity ofthe biological tissues located in chamber 1.

What we claim is:

1. A pulsatory system for pumping liquids comprising: apositive-displacement pump having two chambers divided by an elasticresilient wall, one of said chambers having an opening for the intakeand ejection of liquid, the other one of said chambers communicatingwith a pulsatory pressure source, said opening for the intake andejection of liquid being submerged into the liquid to be pumped andallowing a predetermined layer of the liquid to be pumped between saidopening and a gas medium said liquid to be pumped is located in astorage vessel; an aerator filled with gas and located over said openingso that each batch of liquid to be pumped and ejected due to a pressurepulse on said elastic wall from said opening through said layer of theliquid being pumped, moves onto the walls of said aerator, spills outover said walls of said aerator while saturated with gas, and spillsdown outside from said aerator gas supply means for supplying said gasto said aerator; gas removal means for removing gas from said aerator;an auxiliary chamber communicating with said aerator and receiving saidbatch of liquid from said aerator; and piping connected to saidauxiliary chamber and communicating with said storage vessel forcirculating liquid from said aerator to said storage vessel through saidauxiliary chamber and said piping.

1. A pulsatory system for pumping liquids comprising: apositive-displacement pump having two chambers divided by an elasticresilient wall, one of said chambers having an opening for the intakeand ejection of liquid, the other one of said chambers communicatingwith a pulsatory pressure source, said opening for the intake andejection of liquid being submerged into the liquid to be pumped andallowing a predetermined layer of the liquid to be pumped between saidopening and a gas medium said liquid to be pumped is located in astorage vessel; an aerator filled with gas and located over said openingso that each batch of liquid to be pumped and ejected due to a pressurepulse on said elastic wall from said opening through said layer of theliquid being pumped, moves onto the walls of said aerator, spills outover said walls of said aerator while saturated with gas, and spillsdown outside from said aerator gas supply means for supplying said gasto said aerator; gas removal means for removing gas from said aerator;an auxiliary chamber communicating with said aerator and receiving saidbatch of liquid from said aerator; and piping connected to saidauxiliary chamber and communicating with said storage vessel forcirculating liquid from said aerator to said storage vessel through saidauxiliary chamber and said piping.